A liver transplant donor is in stable condition in the intensive care unit of Queen Mary Hospital following an operation to clean up an infection that developed a week after the transplant. So Po-chun donated part of her liver last Tuesday in the city's first case of cross-family liver transplants. She gave part of her liver to a stranger, a Mr Ma, while Mr Ma's wife donated part of her liver to Ms So's brother-in-law. On Monday there was no hint of any complication as Ms Ma came out to talk to the media with the three other patients about the special transplant. But the next day, she had to have a second operation to clean up an infection to her surgical wound, a hospital spokeswoman said. She denied media reports that the woman would need a liver transplant, adding that the infection was 'a normal complication'. Henry Chan Lik-yuen, director of Chinese University's Centre for Liver Health, said the risk of complications for liver transplant donors was about 5 to 10 per cent. 'These complications are usually not serious, including bile leak, bleeding, wound infection or a gaping wound which requires closing up,' Professor Chan said. 'The liver volume and function usually returns to normal within six months.' There have been very few donor deaths due to severe bleeding or liver failure, he said. Lo Chung-mau, of the University of Hong Kong's department of surgery, who was responsible for the transplants, said: 'I cannot comment on her condition without her consent.' So Wai-lun, 36, was suffering from acute liver failure and was urgently in need of a blood group A-compatible liver. His sister-in-law, So Po-chun, was willing to donate but she belonged to blood group B. Meanwhile, Mr Ma, 47, who suffered from chronic liver cirrhosis, had been waiting for a blood group B-compatible liver for a year, but his wife was blood group A. While donating across blood groups is possible, up to 60 per cent of patients die, because the body rejects the foreign organ. The success rate for transplants with matching blood types is more than 95 per cent. The So family declined to comment about the second operation on Ms So. The other family could not be reached. The family swap offers new hope to the more than 120 people who are waiting for a liver transplant in Hong Kong, as only about four livers a year are donated after deaths. Each year, about 20 per cent of patients are unable to receive a transplant because their donors belong to an incompatible blood group, but with the exchange arrangement it has been estimated half of them could be saved.